Apache Struts 2.0.0 through 2.3.x before 2.3.20 uses predictable <s:token/> values, which allows remote attackers to bypass the CSRF protection mechanism.

Apache Struts 2.x before 2.3.25 does not sanitize text in the Locale object constructed by I18NInterceptor, which might allow remote attackers to conduct cross-site scripting (XSS) attacks via unspecified vectors involving language display.

Multiple open redirect vulnerabilities in Apache Struts 2.0.0 through 2.3.15 allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in a parameter using the (1) redirect: or (2) redirectAction: prefix.

Apache Struts 2.0.0 through 2.3.15.1 allows remote attackers to bypass access controls via a crafted action: prefix.

Apache Struts 2.0.0 through 2.3.24.1 does not properly cache method references when used with OGNL before 3.0.12, which allows remote attackers to cause a denial of service (block access to a web site) via unspecified vectors.

OGNL provides, among other features, extensive expression evaluation capabilities. This vulnerability allows a malicious user to bypass the '#'-usage protection built into the ParametersInterceptor, thus being able to manipulate server side context objects. This behavior was already addressed in S2-003, but it turned out that the resulting fix based on whitelisting acceptable parameter names closed the vulnerability only partially.